package cn.fenqing168.springcloud.lb;

import org.springframework.cloud.client.ServiceInstance;
import org.springframework.stereotype.Component;

import java.util.List;
import java.util.concurrent.atomic.AtomicInteger;

/**
 * @author Administrator
 */
@Component
public class MyLb implements LoadBalancer {

    private AtomicInteger atomicInteger = new AtomicInteger(0);


    public final int getAndIncrement(){
        int current, next;
        do{
            current = atomicInteger.get();
            next = current >= Integer.MAX_VALUE ? 0 : current + 1;
        }while (!atomicInteger.compareAndSet(current, next));
        return next;
    }

    @Override
    public ServiceInstance instances(List<ServiceInstance> serviceInstances) {
        return serviceInstances.get(getAndIncrement() % serviceInstances.size());
    }
}
